新型复合混凝剂在染料废水处理中的应用

The Application of New Composite Coagulant in Dealing with Dye Wastewater

染料废水由于色度高、水质变化大、生化性差等特点,是当前工业废水处理的难点和焦点之一,混凝法是处理染料废水的主要方法之一。本实验采用矿渣、盐酸和硫酸铁、氧化铝研制了一种新型复合混凝剂,以此来处理直接耐晒大红染料废水。采用单因素法分别通过改变废水pH值,混凝的时间以及混凝剂的投加量来观察混凝剂对废水的处理效果。实验结果表明,随着pH值、混凝剂投加量和反应时间的增加,COD及色度都呈现先降低后趋于稳定的变化趋势:当pH值=11时,色度去除率达最大值84.0%,COD去除率达76.1%;当投加量为0.7g时,色度去除率达最大为88.1%,COD去除率为73.2%;当混凝时间为3min时,色度去除率最大为89.3%,COD去除率达76.2%。综上,此混凝剂的最佳反应条件为投加量0.7g,pH值11,混凝时间3min。该新型复合混凝剂处理染料废水效果好,产生的絮体大,沉降速度快,出水清澈透明。

Because the dye wastewater has high chroma,varietied water quality and poor biodegradability,it becomes the most difficult and focused problem in industrial wastewater disposal.Coagulation-Flocculation is one of the main methods in dealing with industrial wastewater.In this experiment,new composite coagulant made from scoria,hydrochloric acid,ferric sulfate and alumina oxide was used to cope with the dye wastewater of direct sunproof scarlet.The single-factor method was taken to observe the treatment effects by changing pH value,dosages of coagulants and reaction time.The results of the experiment showed that,with the increase of pH value,dosages of coagulants and reaction time,both COD and color decreased.COD and color were lower at first and after tended the stabilizing trends.When the pH value equals to 11,the removal rates of color and COD achieved the maximums 84.0% and 76.1%,respectively;When the dosages of coagulants increased to 0.7g,the removal rates of color and COD reached 88.1% and 73.2%,respectively;And when the reaction time was 3 minutes,the removal rates of color and COD reached 89.3% and 76.2%,respectively.From the above,the optimum reaction conditions of coagulation were obtained when pH value was 11,the dosages of coagulant was 0.7g/L,and the reaction time was 3 minutes.This new composite coagulant in dealing with dye wastewater has the characteristics of better efficiency,bigger floc,quicker settling rate and cleaner effluent.